Pump



Jan. 22, 1952 J. GLOVER ET AL PUMP Filed June 23, 1948 INVENTORS GL01/f@ ARI/v/- L. fof/Ns olv ATTO RN EY 5 Jan. 22, 1952 J. A. csLovER Erm. 2,583,421

PUMP

Filed June 23, 1948 2 SIPlEETS-SI'IEET 2 wir INVENTORS ATTORNEYS l/Acuam Patented Jan. Z2, 1952 PUMP John A. Glover, Munster, Ind., and Marvin F. L.

Johnson, Chicago, Ill., assignors, by mesne assignments, to Sinclair Research Laboratories Inc., Harvey, Ill., Ia corporation of Delaware Application June 23, 1948, Serial No. 34,584

(Cl. 21m-83) 4 Claims. l This invention relates to an apparatus which is suitable for use in the positive-displacement circulation of gases in a closed system, and which may beemployed, for example, in the study of gas reactions occurring at constant atmospheric, subatmospheric or superatmospheric pressure.

The apparatus in general comprises two reservoirs, each having a gas inlet line and a gas outlet line, and means for alternately applying pressure and vacuum to volumes of mercury contained in each of the reservoirs one-half cycle apart. The alternate application of pressure and vacuum to the volumes of mercury causes them to be displaced, which displacement effects the desired movement of the gas through the apparatus.

For a more complete understanding of the ap paratus of the present invention, reference is made to the accompanying drawings in which Figs. 1 and 2 represent an embodiment thereof.

In Fig. 1, the numerals I representl the reservoirs, suitably made of glass, having gas inlet lines 2 provided with check valves 3 and having gas outlet lines 4 provided with check valves 5 and 6. The reservoirs are also provided with lines 1 and 8 having check valves 9, through which lines vacuum and pressure are alternately applied to the reservoirs.

Check valves 3, 5, 6 and 9 comprise ground glass surfaces and stainless steel balls.V The steel balls of valves 3, 5, and 9 are supported by indentations I in the reservoirs and are floated into place by the mercury the passage of which they prevent, while the steel balls of valves 6 are weighted down by mercury-filled glass bulbs II, so that those balls are always partially immersed in mercury which forms a seal on the down stroke of the mercury, thus preventing the passage of gas.

In operation, the reservoirs are filled with mercury to the level indicated by the numeral I 2, the two-way stopcocks I3 being opened and the three-way stopcock I4 (which may be used in cleaning the apparatus, in filling it with mercury, and for adjusting the mercury in each reservoir to the same level) being closed. The application of air pressure through the line 1 or 8 to a particular reservoir will force the mercury up and the contained gas out past the check valves and 6. Reversal of the mercury flow is accomplished by applying vacuum to the reser voir through the same line, so that the reservoir again becomes lled with gas which enters past the check valves 3.

In this manner, positive displacement pumpingof the gas takes place in the direction shown by the arrows, sucient mercury at all times being present in the lower chamber 35 of a particular reservoir to block a direct gas connection between the lines 1 or 8 and the upper chamber of such reservoir through the tubes 33 and the holes 39. The tubes 38 are advisedly of large diameter, so that if mercury be lost from the pump through failure of check valves 5 or 9 to function properly the extent of gas loss through the lines 38 to the lines 1 or 8 is thereby decreased. Furthermore, the openings 33 are advisedly made small, in order to prevent excessively high rates of mercury flow, which might cause glass breakage. In addition, since there is a tendency for gas to be drawn down with the mercury by aspiration, the gas inlet tubes from the valves 3 are advisedly connected to the lower part of the chambers 3 1 as shown, rather than to the necks between those chambers and the stopcocks I3.

Thel means for the alternate application of pressure and vacuum to the mercury are shown in detail in Fig. 2. Such means comprise threeway solenoid valves I5 and I-B, which when energized by the electrical system apply vacuum and which when de-energized apply air pressure to the lines 1 and 8, respectively. In Fig. 2, the numeral I1 indicates a mechanical latch-in electrical reset relay having an operating coil I8, a reset coil I9, and contacts 20 and 2|. The relay is of the type in Which one contact is closed while the other is open; this position is maintained by a lock mechanism until energization of the other coil reverses the positions. In one suitable relay, energization of the lower (operating) coil of the relay raises the armature, allowing the latch to drop and hold the armature closed; energization of the upper (reset) coil raises the latch, allowing the armature to drop and open.

The lead wires 22, 23, 24, 25, 26 and 21 are connected, respectively, to the tungsten-throughglass contacts 28, 29, 30, 3|, 32 and 33, respectively. The numeral 34 of Fig. 2 represents a conventional signaling transformer (e. g., /6-8 volts) connected to a source (not shown). A switch 35 is also provided in the high voltage lines leading to the transformer for the switching on and off of the apparatus.

It will be seen that the mercury contained in the apparatus must make contact at both 30 and 3| in order that the reset coil I9 may be en- 3 ergized; likewise, the mercury must make contact at both 32 and 33 in order that the operating coil I8 may be energized. Such an arrangement prevents the mercury in either reservoir from changing direction before the mercury contained in the other reservoir has reached the proper position. As a result of the arrangement shown, when vacuum is applied to one reservoir, pressure is applied to the other; the mercury in one reservoir is on the downstroke while the mercury in the other is on the upstroke.

On the other hand, 'the mercury must be prevented from moving out of a given reservoir in case the mercury on that side makes contact long before the other. Hence, check valves and 9 have been provided. Such check valves would not be absolutely necessary in the event that perfect timing of the apparatus could be obtained; experience has indicated, however, that this is very diflicult, if not impossible, todo.

With proper regulation of the amount of air pressure and vacuum and with suitable adjustment of the stopcocks I3, the two sides oi the apparatus will operate at substantially the same rate, provided they are of the same dimensions, giving a smooth iiow of gas at a pressure which does not vary by more than 11% of the desired pressure. Similarly, the ow rate itself can be adjusted, for example, by adjusting the amount of air p-ressure and vacuum, or by varying the size of the reservoirs.

We claim:

l. An apparatus for producing a constant and even ow of gas comprising a gas outlet conduit; a pair of similar positive-displacement pumping means each having a discharge outlet communieating with said gas outlet conduit; each of said similar pumping means including a gravity type check valve mounted in its discharge outlet, a reservoir depending from and communicating 4 conduit by said power means for elevating and lowering the level of said conducting liquid in said reservoir, a gas inlet conduit communicating with the upper portion of said reservoir, one way valve means mounted in said gas inlet conduit and responsive to said lowering of said conducting liquid to allow entrance of gas to said reservoir; and electrical control means for both of said power means responsive to a predetermined level of conducting fluid in the discharge outlet of one of said pumping means and a complementary predetermined level of conducting iiuid in the upwardly extending conduit of the other of said pumping means for alternately applying high and low pressures to the reservoir of each pumping means one-half cycle with said discharge outlet, power means having apart to alternately elevate and lower the level of conducting liquid contained therein.

2. An apparatus in accordance with claim l and including a rst floating type check valve mounted in said discharge outlet of each of said pumping means betweensaid gas outlet conduit and said gravity type check-valve for preventing the flow of conducting liquid therethrough.

3. An apparatus in accordance with claim 2 and including a second floating type check valve mounted in said upwardly extending conduit for preventing the ilow of said conducting liquid therethrough.

4. An apparatus in accordance with claim 3 and including a valved conduit means interconnecting the bottom of one said reservoir with the bottom of the other for equalization of conducting iiuid level therebetween.

JOHN A. GLOVER. MARVIN F. L. JOHNSON.

REFERENCES CITED The following references -are of record in the le of this patent:

UNITED STATES PATENTS Lago Oct. 7, 

